Within Six Months of Effectively Using Methicillin to Treat S

question 4

Multiple Choice

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new infections were caused by MRSA. How can this result best be explained?

• A) S. aureus can resist vaccines.
• B) A patient must have become infected with MRSA from another community.
• C) In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug.
• D) Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.
• E) The drug caused the S. aureus DNA to change.

---

Definitions:

Cooperative Behavior

Actions taken by individuals or organizations that are designed to benefit others or achieve a common goal through collaboration.

Product Differentiation

Product differentiation is a strategy businesses use to make their products unique and stand out from competitors, often through design, quality, or features.

Price War

A competitive business strategy in which companies repeatedly cut prices to undercut competitors, often resulting in reduced profit margins for everyone involved.

Tacit Collusion

An unspoken, informal agreement among competitors to avoid certain competitive practices, like price wars, to keep prices at a certain level or to divide markets.